Hello Craig:

The knobs on switches such as lights, wipers, etc. all screw off anti-clockwise.

I tried (briefly) to remove the black climate control tabs you speak of and eventually found that by putting the levers in the center of their travel and turning the control box 90 degrees I was able to remove the entire unit from the back of the dash.

I am not quite following what part you are trying to replace. Can you be more specific? On my '67 car there is a semi-transparent VERY flimsy piece of plastic that you should be able to easily slip over the control knobs without removing the tabs. Perhaps you are referring to something else.

Cheers,

Jeff Pucillo